#include<bits/stdc++.h>
using namespace std;

string jd[] = {"4.5", "3.5", "2.5", "1.5", "0", "Error"};
string non_cap = "abcde";
string cap = "ABCDE";

int main()
{
	char ch;
	cin>>ch;
	int num1 = non_cap.find(ch);
	int num2 = cap.find(ch);
	if(num1 != -1)
		cout<<jd[num1];
	else if(num2 != -1)
		cout<<jd[num2];
	else
		cout<<jd[5];
    return 0;
}

